Total parenteral nutrition (TPN) is now widely used as an adjunctive therapy in promoting wound healing, correcting negative nitrogen balance, achieving weight gain, growth and development. This has been accomplished despite little or no knowledge concerning the human intravenous requirements for the micronutrients. This research seeks to determine the levels of vitamins and trace minerals which must be present in TPN infusion fluids to maintain homeostasis in man. Both patients and dogs will be studied. Micronutrient levels in blood and tissues and urinary excretion rates will be measured in dogs receiving TPN with and without micronutrient supplementation. Assuming that there is a general relationship between tissue levels of micronutrients and their concentration in blood and urine, the information obtained in puppies will be used to estimate tissue levels in man from data on blood and urine measurements. The animal data will also determine if there is selective depletion of micronutrients when puppies are fed intravenously. Based on the dog study, patients will be give different doses of micronutrients, and blood and urine levels monitored to estimate intravenous requirements. Vitamins to be studied are: vitamin A, ascorbic acid, vitamin E, thiamine, ribolflavin, folic acid and vitamin B12. Erythrocyte transketolase, glutathione reductase and glutamic oxaloacetic transaminase activities will also be measured for adequacy of thiamine, riboflavin and pyridoxine, respectively. Trace minerals to be studied are: Zinc, copper, manganese, and chromium. This research will improve the care of patients receiving TPN by preventing either a deficiency or toxicity of the micronutrients.